Organically Managed, High Tunnel and Open Field Strawberry, Tomato and Lettuce Variety Trial Research Summary

Jeff Martin and Annette Wszelaki Department of Plant Sciences

Introduction High tunnels extend the production season, and increase earliness of harvest, fruit quality, yield and crop marketability of high-value crops, but have been underutilized in the Southeast. In this study, a comparison of yield and quality of six strawberry varieties, four tomato varieties, and six lettuce varieties was conducted in high tunnel (HT) and open field (OF) production systems using organic management practices. Furthermore, size, firmness, color, soluble solids content, titratable acidity, and the ratio of soluble solids content to titratable acidity were evaluated for the strawberry cultivars. These quality parameters were compared among winter HT, spring HT, and spring OF production systems.

Materials and Methods This study was conducted at the East TN AgResearch and Education Center (ETREC) Organic Crops Unit in Knoxville, TN. Within each tunnel or field plot, one row was dedicated to each of the crops. Each variety plot measured 14 feet long with 28 strawberry plants spaced 1 foot apart in a double staggered row, 7 tomato plants spaced 2 feet apart in a single row, or 28 lettuce plants spaced 1 foot apart in a double staggered row.

Black plastic was laid by hand in the HTs and a plastic layer was used in the OF to make flat beds. Preplant fertilizer (soybean meal: 7.00 total N, 0.40 elemental P, 0.66 elemental K) was applied at a rate of 30 lbs N/acre. Liquid fish fertilizer (2.00 total N, 0.40 elemental P, 0.17 elemental K) was applied via drip tape at a rate of 1 lb N/acre/day once per week.

Insecticides were applied as needed: PyGanic (aphids), M-Pede (silverleaf whiteflies and tarnished plant bug), Aza-Direct (tarnished plant bug), and Dipel (tomato hornworm and true armyworm). Predatory mites were released to control the two-spotted spider mite on strawberries. A class C large earth bumblebee hive was placed in each high tunnel for supplemental strawberry pollination. Three applications of copper hydroxide were applied to tomatoes to prevent late blight.

Winter HT strawberry harvests began 2 December 2011 and continued until 12 January 2012. Fruit quality was measured on 20 berries from each subplot/cultivar, but only 15 berries were tested in the winter HT due to the low number of fruit. Spring HT harvests resumed 2 March and continued until 14 June. Spring OF harvests began 6 April and continued until 29 June.

Tomato harvests in the HT began 14 June (75 DAT) and ended 22 August (144 DAT) while OF harvests began 5 July (60 DAT) and ended 22 August (108 DAT).

Lettuce harvests in the HT began 12 April (43 DAT) and ended 27 April (58 DAT) while the OF harvests began 13 May (42 DAT) and ended 1 June (61 DAT).

Results

Strawberry Trial

Marketable % Avg. Berry Firmness Total Yield Yield Marketable 2011-2012 Size (ozs) (grams) SSC (%) (lbs/plant) (lbs/plant) (lbs/plant) Winter HT San Andreas 0.73 cde 347.0 a 8.79 b 0.09 i 0.02 h 25 g Albion 1.08 a 306.4 ab 9.85 a 0.09 i 0.04 h 49 b-e Seascape 0.83 bcd 330.2 ab 9.84 a 0.04 i 0.02 h 42 e Chandler . . . 0.04 i 0.02 h 17 g Radiance 1.02 ab 242.6 c 9.22 ab 0.18 i 0.11 gh 57 bcd Strawberry Festival 0.87 abc 299.7 b 9.60 ab 0.13 i 0.07 gh 47 def Spring HT San Andreas 0.42 f 182.9 de 5.31 gh 0.66 fg 0.40 de 58 a-e Albion 0.50 ef 184.1 de 5.98 fg 0.49 h 0.22 fg 47 cef Seascape 0.51 ef 155.8 ef 6.30 ef 0.60 gh 0.35 ef 56 b-e Chandler 0.43 f 121.8 f 5.12 hi 0.86 cde 0.49 cde 56 b-e Radiance 0.45 f 197.1 cd 4.55 i 1.06 ab 0.66 ab 61 abd Strawberry Festival 0.52 ef 188.6 de 5.94 fg 0.79 def 0.46 de 57 a-e Spring OF San Andreas 0.55 ef 206.7 cd 6.32 f 0.99 abc 0.64 bc 64 abc Albion 0.59 def 189.9 de 7.59 c 0.73 efg 0.46 de 64 abc Seascape 0.55 ef 194.6 cde 7.45 c 0.75 efg 0.49 de 64 abc Chandler 0.39 f 128.6 f 7.38 cd 0.93 bcd 0.55 bcd 59 bcde Radiance 0.49 ef 201.7 cd 6.73 def 1.06 ab 0.68 b 64 abc Strawberry Festival 0.40 f 214.9 cd 7.04 cde 1.12 a 0.84 a 74 a P value 0.0057 0.0025 0.0077 0.0031 0.0102 0.0010

Quality was highest in the winter HT system but yields were lowest. The spring OF system produced higher yields, but quality was reduced. Albion attained the best quality among cultivars, while Strawberry Festival produced the highest marketable yield (weight and number of fruit).

Tomato Trial

2011 Average Cultivar x Market. % Marketable production Total Yield Yield Marketable Weight per system Location (lbs/ plant) (lbs/plant) (lbs) Fruit Celebrity 17.46 7.43 41.2 bcd 0.19 cd Cherokee Purple High 10.56 4.96 46.2 bc 0.33 a Early Girl Tunnel 19.18 11.79 61.4 a 0.11 f Red Defender 13.93 6.59 47.0 b 0.22 bc Celebrity 10.76 3.79 34.7 cd 0.22 bc Cherokee Purple Open 6.44 2.05 31.8 d 0.30 a Early Girl Field 10.14 6.68 65.8 a 0.15 e Red Defender 9.24 6.04 64.3 a 0.19 cd P-value 0.1418 0.1026 0.0047 <0.0001

HTs increased yields compared to the OF. Early Girl had greater yields than the other three cultivars, and Cherokee Purple had the lowest yields. While lower than other cultivars, Cherokee Purple yields were more than two times greater in the HT versus the OF production system, and price premiums attained for organic heirlooms can help offset yield differences.

Lettuce Trial

2011 Cultivar x Production Total Yield Market. Yield % Marketable System Location (lbs/plot) (lbs/plot) (lbs/plot) New Red Fire 17.64 c 17.42 cde 99 a Green Star 27.56 b 25.35 b 92 ab High Ermosa 29.32 b 15.87 cde 54 c Tunnel Adriana 32.63 b 18.08 b-e 55 c

Jericho 48.06 b 21.61 bc 45 d Coastal Star 43.65 a 41.01 a 94 b New Red Fire 12.79 e 12.79 def 100 a Green Star 17.42 de 17.42 cde 100 a Ermosa 20.28 cd 19.84 bcd 98 a Open Adriana 23.59 c 22.05 bc 93 ab Field Jericho 61.51 a 5.73 f 9 f Coastal Star 50.49 b 11.02 ef 22 e P-value <.0001 <.0001 <.0001

HTs increased total yields compared to the OF except the cultivars Jericho and Coastal Star, and HTs increased marketable yields for Green Star, Jericho and Coastal Star. The OF had higher percent marketable yields excluding Jericho and Coastal Star. Bolting occurred more often in the HTs compared to the OF, due to increased temperature.

Special thanks for funding provided through the USDA Specialty Crops Research Initiative. Grant Award No. 2009-51181-05897

2013 Organically Managed Pepper Variety Trial J. Martin, M. Deleon, C. Sullivan, G. Duesterbeck, M. Rogers, J. Moore, and A. Wszelaki Department of Plant Sciences

Introduction

Pepper production in Tennessee consists of sweet, hot, and pimento cultivars. On average, Tennessee produces 700 to 900 acres of peppers and 75 percent of those are bell types. Nearly all the bell peppers are produced for fresh market, and Tennessee contributes ten percent of total U.S. bell pepper production. Cost varies in pepper production with the highest cost occurring when hybrid varieties are grown as these seeds carry a greater cost than non-hybrid seed. Hybrid seeds can lead to greater yields and better quality fruit. The purpose of this trial was to evaluate six pepper varieties grown organically.

Materials and Methods

This study was conducted at the ETREC Organic Crops Unit in Knoxville, TN. Six week old plants were transplanted 8 May. A total of 6 varieties were evaluated and replicated 4 times in a randomized complete block design. Each plot measured 15 feet long with 10 plants spaced 3 feet apart in a double-staggered row with row spacing of 5 feet.

Fertilizer, 90 lb/acre (Nature Safe 8-5-5), was broadcast in the planting rows 2 weeks after transplanting. Plants were initially irrigated when transplanted, but supplement irrigation was not needed due to the large amount of rain received.

Plants were scouted once a week for insects and diseases but no chemical applications were necessary. The brown marmorated stink bug caused significant damage to the fruit but no organic controls are currently available.

Harvest data shown here represents the time period between 12 July (65 days after planting) and 14 August (90 days after planting).

Total Marketable No. of % Marketable Yield/Plant Yield/Plant harvests (lbs) (lbs) (lbs) Variety 900 (EZ) 5 0.94 0.35 b 37 bc Sprinter (EZ) 5 0.77 0.18 b 23 c Milena (EZ) 5 1.32 0.60 a 47 ab Abay (EZ) 5 0.79 0.22 b 24 c Lipstick (JS) (pimiento) 5 1.11 0.61 a 55 a Sweet chocolate (PV) 4 0.57 0.23 b 41 b p value 0.0596 0.0004 0.0011

2013 Organically Managed Tomato Variety Trial

J. Martin, M. Deleon, C. Sullivan, G. Duesterbeck, M. Rogers, J. Moore, and A. Wszelaki Department of Plant Sciences

Introduction

Tomato production in Tennessee ranks fourth in the country and makes up 3 percent of the U.S. fresh market tomato industry. On average, more than 4,000 acres are planted annually and is estimated to be valued at $10 million. Many growers utilize greenhouses for out of season tomato production and tomato production costs vary. Tomato varieties differ among operations, and both hybrid and heirloom varieties are used for fresh market production. Hybrid seeds generally carry a higher price but higher quality and yield may offset seed costs. The purpose of this study was to compare six varieties of tomato grown organically.

Materials and Methods

This study was conducted at the ETREC Organic Crops Unit in Knoxville, TN. Six week old plants were transplanted 14 May. A total of 6 varieties were evaluated and replicated 4 times in a randomized complete block design. Each plot measured 20 feet long with 10 plants spaced 2 feet apart in a single row with row spacing of 5 feet.

Fertilizer, 90 lb/acre (Nature Safe 8-5-5), was broadcast in the planting rows 2 weeks after transplanting. Plants were initially irrigated when transplanted, but supplement irrigation was not needed due to the large amount of rain received.

Plants were scouted once a week for insects and diseases and no insecticidal applications were necessary. Due to the wet and cool summer, preventative measures were taken to prevent the onset of fungal diseases. Two sprays of copper hydroxide (77% a.i. (Champ WG; Albaugh, Inc., Ankeny, IA)) at label rate of 80 grams per gallon water were applied on 12 and 26 July.

Harvests began 14 May (62 days after planting) and ended 14 August (92 days after planting). Fruits were weighed by plot and then divided by the number of plants to determine the weight per plant.

No. of Total Marketable % Marketable Harvests Yield/Plant (lbs) Yield/Plant (lbs) (lbs) Variety Montesino (EZ) (grape) 15 5.39 b 5.37 b 99 a Toronjina (EZ) (cherry) 16 7.22 a 7.01 a 97 b p value 0.0155 0.0188 0.0132

Watonga (EZ) 11 8.17 a 7.42 a 90 a 687 (EZ) 10 5.18 bc 4.54 b 87 a Cherokee Purple (SoC) 12 6.91 ab 4.23 b 63 b Valencia (PV) 10 3.87 c 3.36 b 87 a p value 0.0417 0.0169 0.0041 Seed source: EZ=Enza Zaden, PV=Peaceful Valley and SoC=Seeds of Change

2013 Organically Managed Zucchini Variety Trial

J. Martin, M. Deleon, C. Sullivan, G. Duesterbeck, M. Rogers, J. Moore, and A. Wszelaki Department of Plant Sciences

Introduction

Squash and zucchini production for both fresh market and processing is an important commodity in Tennessee. Tennessee produces 2 to 3 % of U.S. produced squash and zucchini with the majority being grown for the fresh market. In recent years, squash and zucchini production has decreased from 1,500 acres in 2002 to 700 acres in 2011. However, fresh market consumption continues to demand high quality fruits. Hybrid seeds are becoming increasingly popular. Their ability to tolerate pest pressure and resist diseases has become more and more attractive to growers. This study focused on yield and marketability of two varieties of summer squash grown organically.

Materials and Methods

This study was conducted at the East TN AgResearch and Education Center (ETREC) Organic Crops Unit in Knoxville, TN. Plants were direct seeded 12 June. A total of 2 varieties were evaluated and replicated 4 times in a randomized complete block design. Each plot measured 20 feet long with 10 plants spaced 2 feet apart in a single row with row spacing of 4 feet.

Fertilizer, 90 lb/acre (Nature Safe 8-5-5), was broadcast in the planting rows once plants grew 2 to 3 true leaves. Plants were initially irrigated when seeded, but supplement irrigation was not needed due to the large amount of rain received.

Plants were scouted every two days for insects and diseases but no chemical applications were necessary. Squash bug adults and eggs were hand-picked during field scouting to reduce pest populations.

Harvests began 15 July (33 days after planting) and concluded 14 August (63 days after planting). Fruits were weighed by plot, and then divided by the number of plants to determine the weight per plant.

Total Marketable No. of % Marketable Yield/Plant Yield/Plant Harvests (lbs) (lbs) (lbs) Variety Dunja (EZ) 23 3.45 3.19 93 Desert (EZ) 22 3.92 3.62 93 p value 0.6957 0.6643 0.9798

2013 Organically Managed Melon Variety Trial

J. Martin, M. Deleon, C. Sullivan, G. Duesterbeck, M. Rogers, J. Moore, and A. Wszelaki Department of Plant Sciences

Introduction

Cantaloupe production is an important commodity when it comes to Tennessee’s agricultural system and comprises 1 percent of the U.S. acreage. Cantaloupe production contributes close to $5 million into the state’s agricultural economy with about 1,000 acres of commercial cantaloupes grown each year. Weather is a major factor that determines the amount of cantaloupes grown and harvested in a given year. Cantaloupes are very sensitive to cool temperatures and growth is stunted if exposed to temperatures below 50 ⁰F. Large amounts of rain also reduce the sugar content and cause the skin to crack prior to ripening. In recent years selected hybrid varieties have significantly increased production for wholesale markets. This study focused on yield and marketability of two varieties of Italian netted melons, Magnificenza and Tirreno, grown organically.

Materials and Methods

This study was conducted at the ETREC Organic Crops Unit in Knoxville, TN. Plants were direct seeded 12 June. A total of 2 varieties were evaluated and replicated 4 times in a randomized complete block design. Each plot measured 20 feet long with 10 plants spaced 2 feet apart in a single row with row spacing of 8 feet.

Fertilizer, 90 lbs/acre (Nature Safe 8-5-5), was broadcast in the planting rows once plants grew 2 to 3 true leaves. Plants were initially irrigated when seeded, but supplement irrigation was not needed due to the large amount of rain received.

Plants were scouted once a week for insects and diseases but no chemical applications were necessary.

Cantaloupes have not been harvested yet.

For more information, contact Annette Wszelaki at [email protected] or 865.974.8332, or visit http://organics.tennessee.edu or http://vegetables.tennessee.edu.

Special thanks to Bill Lively, Lee Ellis and Bobby Simpson of the East TN AgResearch and Education Center.